I'm using an acrylic lacquer basecoat to paint my motorcycle tank and fendors. From what I have read lacquer based paints are not gasoline resistant so I want to use a urethane based clear coat. I was planning to do flames also and clearcoating the base coat before adding the flames. Will I have problems painting urethane over lacquer or vice versa lacquer over urethane?
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Clear Coat Compatiblity
- Thread starter Hyme
- Start date
B
blazer73
Guest
Yes you will run into problems,,dont do that,,save yourself a huge dissapointment,,use compatable materials
A
abkrdude
Guest
man, I hear ya about the compatibility worry. I had just got my tank looking good, used an enamel paint, then went and bought a can of "Crystal Clear Acrylic" to top coat. Not sure if it was the compatibility issue or not, but I got a bad wrinkle (orange peel) look to it in spots. I then worried about it not being "gas" proof and also not being too compatible with the color coat so I went and bought a can of High Gloss Clear Enamel, wet sanded it good, and coated it with that. It shines good now, but I still worry about it down the road after a year or so and after I dribble a little gas on it a time or two???? Anybody else out there with more good advice?
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Aerox
Guest
PPG makes a urethane clear (DAU75 I believe) thats designed to work as a topcoat for lacquer. It works awesome, though you do need to shoot about 4-5 coats as its a reasonably thin medium. It says on the tech sheet not to color sand and polish, but this mainly for production work where they want to sand within hours. Let it sit for a week, hit it with 1500-2000 then use Meguires fine cut cleaner and a foam pad. With the costs of urethane basecoat/clearcoat products today this is a much more cost effective method.
I think Aerox is right with the product #,but I'm relying on memory.I won't use these myself though.I used RM's 2K clear years ago which is the equivolent and it was nice,but then it started.Urethane has a tendancy to be 'hot',and eats lacquer.They toned it down to stick and not eat it up,but.In my experience,the urethane 'melts' the top of the lacquer and had to rely on chemical adhesion.It'll stay until it gets chipped,then it will continue to peel off,and if you look close,if you sanded before the clear the sand scratches are melted away.If you have to repair it later and break thru the clear,it usually won't feather and almost everything lifts and wrinkles the edge.There are a few primers to help in problems like this,but they are a patch for a problem that shouldn't have happened in the first place.I haven't played with this stuff in years so there might be an improvement by now (but the DAU75 is old technology),but this practice is a big no in my book.To me the only reason to use lacquer is to get that little extra depth you just can't quite duplicate with urethane,but you have to be willing to deal with the care and maintenance of having it.Think of it this way:your lacquer is always shifting and moving around because it's soft while the urethane clear sets up hard and doesn't move.This stresses the adhesion of the 2.As long as the clear is 'wrapped' it's fine,but a chip and all hell breaks lose.Same as candying or clearing bare metal.Put a sanding or grinding pattern on bare steel and candy it and it is really cool,but same deal kind of.As long as the clear wraps it you won't have a prob.Ultra motorcycles was doing this,but I don't know if they still are.Go lacquer or urethane,don't mix.This is my opinion only of course.
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abkrdude
Guest
I missed the boat somewhere, so if I paint with what the manufacturer labels "High Gloss Clear Enamel" (or any enamel for that matter), is it a laquer or urethane? Because I am almost sure I have seen coatings labeled "urethane enamel" or "acrylic enamel" and I believe even "acrylic urethane"?
I'm not sure about the urethane enamel,so I won't touch it.There are 4 types of paint for our subject;lacquer,enamel,urethane and waterbourne (water based).The latter is for California and any place that has those tight restrictions on pollution.Lacquer became acrylic lacquer to make it better,same for enamel(plain enamel is called alkyd enamel,then acrylic).I don't know how many types of urethane there are,but I've used acrylic and poly.Polyurethane is the likes of Imron and Durethane.Great fleet paint,but I think it's way too brittle for nice stuff.Acrylic urethane is what everyone uses now for serious paintwork.Enamels are still used,but usually only in cheap jobs.A few things to remember:don't mix types of paint (lacquer,enamel,etc.) and don't mix brands of the same type (ie. don't PPG clear over Dupont base).You will probably have a problem,and the paint manufacturer wont warrantee a thing if they find out you even used someone elses primer.Hope this helps.
S
Sole
Guest
Aerox is right in suggesting the dau75 clear.
My tank was painted about two years ago with PPG basecoat clearcoat and I wanted to paint flames and a mural on. I sanded it with 1500 grit paper and did all the flames and mural on it with lacquer and then sprayed the dau75 on. Buffed it out and it looks great.
good luck.
Mike
My tank was painted about two years ago with PPG basecoat clearcoat and I wanted to paint flames and a mural on. I sanded it with 1500 grit paper and did all the flames and mural on it with lacquer and then sprayed the dau75 on. Buffed it out and it looks great.
good luck.
Mike
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abkrdude
Guest
Rex, I think this is all well and good information. Scott, if your out there, maybe consider adding a brief info section in your how to section... maybe under helpful hints? But if I were to do my paint job again (which I most likely will in a year or so), I will buy all the stuff I think I am going to need upfront, so it is all the same kind and same brand. This job I am just finishing I bought a little here, a little there. Also what about best compatibility with factory paint then? And I could use reference to a good source for very small quantities, almost like the mini bottle size that's for models? I want to try air brush on a mural with multiple colors and shades of colors.
Thanks for the info.
Thanks for the info.
Thanks for all of the replies. I've made the decision to use House of Kolor C-1 Lacquer Clear. I'm painting this over a rattle can paint job (Duplicolor Mirage). I'm crossing my fingers that everything will work. A couple more questions:
Everyone I've talked to in the local paint stores have said that there isn't much of a problem mixing brands as long as they are the same type of paint (i.e. lacquer based). Everything I read in the message board contradicts this. Is this a major issue or is it a strategy by the paint manufacturers to "scare" you into using all of their products? I know they want guarantee anything but do they really guarantee it if you use all their products anyway? To much "user error" to pin it down on the paint itself.
I also plan to lay down some ghost flames over the Duplicolor Mirage using HOK white pearl mixed with the above mentioned clear. Any suggestions on what ratio to mix pearl to clear? I want the flames to be translucent but still noticable.
Thanks
Everyone I've talked to in the local paint stores have said that there isn't much of a problem mixing brands as long as they are the same type of paint (i.e. lacquer based). Everything I read in the message board contradicts this. Is this a major issue or is it a strategy by the paint manufacturers to "scare" you into using all of their products? I know they want guarantee anything but do they really guarantee it if you use all their products anyway? To much "user error" to pin it down on the paint itself.
I also plan to lay down some ghost flames over the Duplicolor Mirage using HOK white pearl mixed with the above mentioned clear. Any suggestions on what ratio to mix pearl to clear? I want the flames to be translucent but still noticable.
Thanks
Hyme
I'd might run toward the faster side on the thinner just to be on the safe side.Usually thinners have an overlap on the temp range.The slower you go with the thinner the farther down it penetrate,try to keep it from softening up too much of the base since alot of rattlecan paint is questionable.The guy in the paint store is right to an extent.If you have acrylic lacquer,you can use pretty much anyone's clear and thinners.The urethanes are where problems start.There are generic companies like Rubber Seal that make clears,paints and primers that can be mixed.Their clear is pretty good and I've never had a prob over PPG's DBC base,but I didn't try it over DBU base because of the reactive reducer(has hardner in it).Hardner incompatability is a big prob when you get to mixing some of this stuff.All the major makers make the same stuff basically,but the chemical composition of DuPont's clear,bases,hardners,etc are a little different than PPG or BASF,etc.I'm no chemist so I don't try to figure it out and experiment.On the pearl,read the label.It doesn't take alot,and I usually go less for ghosting.Spray out a test panel first.If it's a little light put some more in,and make another test panel.Just remember to do it in 2 or 3 coats,not just one.
Abkrdude
Going over a factory finish is fine if it's been done in the last 10 +/- years.Everyone is using good stuff now,but make sure it's sound.For example the Ford problem a few years ago with the paint peeling.This is a classic example of mixing lines.My understanding of the prob was they bought products from the lowest bidder,so the primer,base and clear weren't from the same company(at least that was the last scoop I heard about it).If you took a razor blade to it the base would sheet right off the E-coat.The funny thing was Ford kept telling us the E-coat was coming off the metal.They didn't even believe it when you showed them in person.Watch for factory repaints too.They are just run back through the booth while the paint is soft,but hard enough it all doesn't mix.If you sand through the first layer,the previous job is glossy.The top is stuck,but barely,it won't feather out and bullseyes real bad.Getting small quantities could be tough.If you bought quite a few you might get the paint store to mix 1/2 pints,but I doubt they'd go less.You can mix small amounts,but sometimes you lose the color.Hope this helps guys.
I'd might run toward the faster side on the thinner just to be on the safe side.Usually thinners have an overlap on the temp range.The slower you go with the thinner the farther down it penetrate,try to keep it from softening up too much of the base since alot of rattlecan paint is questionable.The guy in the paint store is right to an extent.If you have acrylic lacquer,you can use pretty much anyone's clear and thinners.The urethanes are where problems start.There are generic companies like Rubber Seal that make clears,paints and primers that can be mixed.Their clear is pretty good and I've never had a prob over PPG's DBC base,but I didn't try it over DBU base because of the reactive reducer(has hardner in it).Hardner incompatability is a big prob when you get to mixing some of this stuff.All the major makers make the same stuff basically,but the chemical composition of DuPont's clear,bases,hardners,etc are a little different than PPG or BASF,etc.I'm no chemist so I don't try to figure it out and experiment.On the pearl,read the label.It doesn't take alot,and I usually go less for ghosting.Spray out a test panel first.If it's a little light put some more in,and make another test panel.Just remember to do it in 2 or 3 coats,not just one.
Abkrdude
Going over a factory finish is fine if it's been done in the last 10 +/- years.Everyone is using good stuff now,but make sure it's sound.For example the Ford problem a few years ago with the paint peeling.This is a classic example of mixing lines.My understanding of the prob was they bought products from the lowest bidder,so the primer,base and clear weren't from the same company(at least that was the last scoop I heard about it).If you took a razor blade to it the base would sheet right off the E-coat.The funny thing was Ford kept telling us the E-coat was coming off the metal.They didn't even believe it when you showed them in person.Watch for factory repaints too.They are just run back through the booth while the paint is soft,but hard enough it all doesn't mix.If you sand through the first layer,the previous job is glossy.The top is stuck,but barely,it won't feather out and bullseyes real bad.Getting small quantities could be tough.If you bought quite a few you might get the paint store to mix 1/2 pints,but I doubt they'd go less.You can mix small amounts,but sometimes you lose the color.Hope this helps guys.